Biotech Updates

Circadian Rhythms Influence Plants' Freezing Tolerance

April 20, 2011

The biological circadian clock has been known to influence various physical, mental, and behavioral changes in all living things. For instance, monarch butterflies depend on circadian cues to begin their annual migration. Michael Thomashow of Michigan State University and colleagues discovered that the circadian clock provides key inputs needed for plants to achieve maximum freezing tolerance.

The researchers identified the C-repeat binding factor or CBF response pathway, which is a stress pathway present in several plants and functions in freezing and drought tolerance. Two core components of the clock (CCA1 and LHY) were found to contribute in the regulation of CBF response pathway. Circadian regulation and cold induction of CBF regulon genes were reduced in plants with the mutated clock components. According to  Thomashow, the results of the study could help scientists in developing "designer plants"- those that have modified CBF pathways to enhance abiotic stress tolerance.

The complete article published at the Proceedings of the National Academy of Sciences in the United States of America is available at